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Medical Images Visualization at the Medical Images Visualization at the
Computer Graphics Group/UFRGSComputer Graphics Group/UFRGS
Carla Maria Dal Sasso Freitas
February, 2000
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SummarySummary
1. Introduction
3. CG Group overviewPrevious works
4. Current project: VPat
5. Final comments
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1. 1. IntroductionIntroduction
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Porto Alegre
470,25 km2
Population: ~ 1,286.251
Climate: Subtropical wet with four well-defined seasons
1. 1. IntroductionIntroduction
Higher education: 4 large universities (each one with more than 20K students) and several small colleges
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UFRGS (Federal University of Rio Grande do Sul)• Created in 1895• One of the top five universities in Brazil, both in size and
quality• ~ 2,278 faculty members• Students: ~ 25,286 (undergraduate and graduate)
1. Introduction1. Introduction
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Informatics Institute
Teaching and research since 1968
Established as an Institute in 1989
Departments• Applied Computing• Theoretical Computing
1. Introduction1. Introduction
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Faculty• 69 professors (INPG, Grenoble; Karslruhe and Stuttgart,
Germany; Newcastle, UK; Stanford, USA; Coimbra, Portugal; Louvain, Belgium; Amsterdam, Netherlands; ...)
• Students: 700 undergraduate level + 270 graduate level
Courses at graduate level• M.Sc. in Computer Science
• Ph.D. in Computer Science
• Professional education
1. Introduction1. Introduction
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Research areas• Computer Graphics and Image processing
• Computer Architecture/Parallel Processing
• Microelectronics/Digital Systems
• Data Base Systems
• Fault Tolerance
• Software Engineering
• Theoretical Computer Science
• Artificial Intelligence
• Computational Mathematics
• Computer Networks/Communication
• Formal Methods
1. Introduction1. Introduction
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2. 2. CG Group OverviewCG Group Overview
Started in 1978, with one professor only
People4 Professors
1 Post-doc
5 Ph.D. Students
18 M.Sc. Students
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Research in the 80's: CAD
Research in the 90's
Rendering and animation
Scientific visualization • Meteorological data• Geological data• Medical images
Image processing techniques
2. CG Group Overview2. CG Group Overview
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Previous works regarding medical images
Nedel at EPFL
Freitas and group at UFRGS
3. CG Group Overview3. CG Group Overview
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Previous works
Nedel at EPFL
Freitas and group at UFRGS
3. CG Group Overview3. CG Group Overview
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Previous works
Nedel at EPFL
Freitas and group at UFRGS
3. CG Group Overview3. CG Group Overview
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3. 3. VPat (VPat (Visualization and interaction with Virtual PatientsVisualization and interaction with Virtual Patients))
Generation of virtual human models (virtual patients) to use in medical applications such as simulation of surgery and training
Movement simulation
Development of a framework to guarantee software reuse
Integration of the existing tools
Goals
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Activities
Design of the OO framework
Volume visualization
3D reconstruction of the human parts from real data
Motion simulation and body deformation (anatomic simulation of human bodies)
3. VPat3. VPat
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Activities
Design of the OO framework
Volume visualization• RenderVox improvement and conversion to the VPat
framework
• Survey about collaborative visualization
• Multimodal visualization
3D reconstruction of the human parts from real data
Motion simulation and body deformation (anatomic simulation of human bodies
3. VPat3. VPat
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Multimodal visualization with RenderVox • MRI and PET data obtained from different patients, no
registration algorithm used
(Marcelo Silva, 2000)
3. VPat3. VPat
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Multimodal visualization: ongoing work• Data obtained from the same patient• Cooperation with the best hospital in Brazil
~ INCOR/University of Sao Paulo
• Study of registration methods
(Isabel Manssour’s PhD thesis)
3. VPat3. VPat
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Activities
Design of the OO framework
Volume visualization
3D reconstruction of the human parts from real data• Marching cubes implementation
• Study of multi-resolution techniques
Motion simulation and body deformation (anatomic simulation of human bodies)
3. VPat3. VPat
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Activities
Design of the OO framework
Volume visualization
3D reconstruction of the human parts from real data
Motion simulation and body deformation (anatomic simulation of human bodies)• Mechanical modeling of joints
• Skeleton motion control
• Soft tissue deformation
3. VPat3. VPat
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Surgery simulation
(Luciana Nedel, 1999)
3. VPat3. VPat
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Activities
Design of the OO framework
Volume visualization
3D reconstruction of the human parts from real data
Motion simulation and body deformation (anatomic simulation of human bodies)
3. VPat3. VPat
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4. 4. Final commentsFinal comments
Interactive segmentation of medical images
• Olabarriaga, 1999 with A. Smeulders, Amsterdam
Development of new filtering techniques
• Scharcanski & Jung, 1999/2000
~ultrasound images from fetal hearts
~mammographic images
Related works in our group
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http://www.inf.ufrgs.br/cghttp://www.inf.ufrgs.br/cg
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Goal: Medical data visualization overview
• Different approaches for collaborative visualization
• To get knowledge about difficulties for its utilization
(WSCG 2000, February 7-11, Plzen)(WSCG 2000, February 7-11, Plzen)Collaborative Visualization in MedicineCollaborative Visualization in Medicine
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Collaborative Visualization in MedicineCollaborative Visualization in Medicine
CSCW (Computer Support for Cooperative Work)• New successful area
• People in different places working together
CSCV (Computer Support for Collaborative Visualization)• Subset of CSCW applications
• Shared visualization and control parameters
• Challenge: multi-user interactive applications
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Visualization pipeline (Haber & McNabb, 1990) extension to achieve collaboration
Collaborative Visualization in MedicineCollaborative Visualization in Medicine
Shared Control Shared Data
Filtering(F) Mapping(M) Render(R)
Image
Data
Filtering(F) Mapping(M) Render(R)
Image
Data
User A
User B
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Collaborative visualization systems applied to Medicine• Image presentation to remote collaborators
• Image-based interaction
Collaborative Visualization in MedicineCollaborative Visualization in Medicine
Telemedicine• Communication technology used to support
interaction between physicians and patients
• Applications~Remote clinical consultation~Telesurgery, teleradiology~Collaborative diagnosis
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TeleInViVo
• Fraunhofer Center for Computer Graphics, DARPA e MATMO
• Main goals~Therapy planning and
treatment~Medical training,
surgery and diagnosis
Collaborative Visualization in MedicineCollaborative Visualization in Medicine
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TeleMed• Los Alamos National Laboratory and National Jewish Center
for Immunology and Respiratory Medicine
• Prototype of the Virtual Patient Records (VPR)
Collaborative Visualization in MedicineCollaborative Visualization in Medicine
• Main goal~Standardize the
electronic management of patient information
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Current trend• Use of the Web as a collaboration environment
Challenges and open questions
Collaborative Visualization in MedicineCollaborative Visualization in Medicine
• Communication technology
• Identification (security) handling
• Shared data coherence
• Synchronization of user activities
• User-friendly interface
• Real-time visualization and interaction
• VR devices accuracy and touch-feedback
• Realistic images
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The building of a collaborative system is an interdisciplinary effort• User-centered approach
• Efficient data management
• Object-oriented design and programming
Collaborative Visualization in MedicineCollaborative Visualization in Medicine
Collaborative systems have to be improved to become attractive work tools
Several difficulties for the real utilization of such systems are still found
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Anatomic modeling of skeletons
Joints positionThe skeleton
( Luciana Nedel, 1998)
Nedel at EPFLNedel at EPFL (Ph.D. Thesis)(Ph.D. Thesis)
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Nedel at EPFLNedel at EPFL
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Simulation of the muscles action
Action lines
• Represent mechanically the force that a muscle produces on a bone
• Composed by an origin, an insertion and optionally by one or more control points
(Luciana Nedel, 1998)
Nedel at EPFLNedel at EPFL
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Muscles deformation
Mass-spring deformation model
• Example: compression • Example: extension
(Luciana Nedel, 1998)
Nedel at EPFLNedel at EPFL
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Example: reconstructed muscle
(Luciana Nedel, 1998)
Nedel at EPFLNedel at EPFL
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Framework to allow the human body modeling and simulation
Body Builder Plus - integration tool
• Allows the design of human models created entirely with bones and reconstructed muscles
• Combines deformable muscles with metaballs representing some muscles, organs and fat tissues
Nedel at EPFLNedel at EPFL
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Body Builder Plus: examples...
(Luciana Nedel, 1998)
Nedel at EPFLNedel at EPFL
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Interactive volume visualization of medical images using ray casting
Available toolsNavigation through the slices data set
Cutting planes
Cutting volume/ subvolume
Hybrid (geometric and volume) visualization
Multimodal visualization
RenderVoxRenderVox
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Camera control and slice visualization
Marcelo Silva, 1999
RenderVoxRenderVox
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Interactive interface
(Marcelo Silva, 1998/2000)
RenderVoxRenderVox
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MRI of a head
(Marcelo Silva, 1998)
RenderVoxRenderVox
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(Marcelo Silva, 1998)
Transparency levels using classification tables
RenderVoxRenderVox
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(Marcelo Silva, 1998/1999)
Cutting with planes
RenderVoxRenderVox
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(Marcelo Silva, 1998/1999)
Cutting with volumes
RenderVoxRenderVox
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Cutting with non-planar tools
Cutting with planes and volumes
(Marcelo Silva, 1998/1999)
(Marcelo Silva, 1998/1999)
RenderVoxRenderVox
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Hybrid rendering (geometric models & volume data)
(Marcelo Silva, 2000)
RenderVoxRenderVox
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Visualization of layers 1 and 2 of characteristic “Marcos de Inundação”, grid dimension 30 x 30, layer 1 in wireframe
(Karen Basso, 1999)
GeoVisGeoVis
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Visualization of layer 1 of characteristic “Marcos de Inundação”, and “Isolita” attribute.
(Karen Basso, 1999)
GeoVisGeoVis
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Isocontour map for attribute “Percentualde Areia”, in layer 1 of “Marcos de Inundação”
(Karen Basso, 1999)
GeoVisGeoVis
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